The main study entitled "A Phase I Study to Evaluate the Safety and Immunogenicity of Recombinant HIV -1 Envelope Antigen in Children Born to HIV-Infected Mothers (ACTG 230 version 7.0, 5/5/97) closed to accrual. ACTG 707 is a substudy of ACTG 230 in which the safety and immunogenicity of HIV vaccines were being evaluated. Participants in ACTG 707 were selected from a subset of approximately 90 children who were in ACTG 230 and are eligible to participate in ACTG 707 because they had a positive response to the vaccine antigens while participating in ACTG 230. The presence of immune responses to vaccine antigens at the final study point (week 104 in ACTG 230) suggested that the study of the durability of these responses beyond 104 weeks would be useful. ACTG 707 will continue to study the lymphoproliferative and humoral responses to vaccine antigens once each year for two additional years past the study period (i.e., weeks 156, and 208) in those patients identified as having a stimulation index (SI) on the LPA assay of 3.0 or greater on at least 2 occasions post-baseline during the ACTG 230 two-year study period.